/**
 * Copyright (C) 2010-2013 Alibaba Group Holding Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.rocketmq.common.filter;

import java.net.URL;

import com.alibaba.rocketmq.common.protocol.heartbeat.SubscriptionData;

/**
 * @author shijia.wxr<vintage.wang@gmail.com>
 * @since 2013-6-15
 */
public class FilterAPI {
	public static String simpleClassName(final String className) {
		String simple = className;
		int index = className.lastIndexOf(".");
		if (index >= 0) {
			simple = className.substring(index + 1);
		}

		return simple;
	}

	public static URL classFile(final String className) {
		final String javaSource = simpleClassName(className) + ".java";
		URL url = FilterAPI.class.getClassLoader().getResource(javaSource);
		return url;
	}

	public static SubscriptionData buildSubscriptionData(final String consumerGroup, String topic, String subString) throws Exception {
		// A）初始化SubscriptionData对象，将topic赋值给该对象的topic变量
		SubscriptionData subscriptionData = new SubscriptionData();
		subscriptionData.setTopic(topic);
		subscriptionData.setSubString(subString);

		// B）检查subExpression是否为空或为"*"，若是则给SubscriptionData对象的subString变量赋值为"*"；
		if (null == subString || subString.equals(SubscriptionData.SUB_ALL) || subString.length() == 0) {
			subscriptionData.setSubString(SubscriptionData.SUB_ALL);
		} else {
			/**
			 * C）否则置subString变量为subExpression参数值；
			 * 对于多个subExpression则以"||"分隔，将subExpression拆分成单个subExpression，
			 * 并存入SubscriptionData.tagsSet:Set<String>集合中；
			 * 并且将每个subExpression进行hash之后，存入SubscriptionData.codeSet :Set<Integer>集合中；
			 */
			String[] tags = subString.split("\\|\\|");
			if (tags != null && tags.length > 0) {
				for (String tag : tags) {
					if (tag.length() > 0) {
						String trimString = tag.trim();
						if (trimString.length() > 0) {
							subscriptionData.getTagsSet().add(trimString);
							subscriptionData.getCodeSet().add(trimString.hashCode());
						}
					}
				}
			} else {
				throw new Exception("subString split error");
			}
		}

		return subscriptionData;
	}
}
